FLOAT Key Control @ vrch.ai

Before you buy a midi controller or wire up a gamepad, try this: hold down a function key and tap up and down. The FLOAT Key Control node turns your keyboard into a live parameter scrubber, and it's the cheapest possible way to get hands on a realtime ComfyUI workflow.

What it is

The mechanism is dead simple. shortcut_key1 picks your modifier key - a function key by default (F2, from a list of 24) - and shortcut_key2 picks the pair of arrows that nudge the value, either Down/Up or Left/Right. Hold the function key, tap an arrow, and current_value moves by step_size (0.01 by default, capped at 0.1). The node outputs that value as FLOAT, which you wire into anything that eats a float: a denoise strength, a CFG, a blend amount, an expression control. current_value starts at 0.5, and since it's a live input on the node you can also just type a starting point before you run.

The interesting toggle is new_generation_after_pressing. Turn it on and every keypress that actually changes the value kicks off a new generation - which is what makes this feel like a performance instrument rather than a settings panel. Combined with ComfyUI's instant auto-queue, you press, it re-runs, you watch the output move. This is the zero-cost entry point to the whole "control it live" scene that this pack is known for.

Common issues

One honest caveat from people who've been there: keyboard control in ComfyUI only fires when the ComfyUI window has focus. There's a long-running thread on r/comfyui from someone trying to use these control nodes while playing a game - ComfyUI just won't see the keys when the window is in the background, because it never grabs a global keyboard hook. So plan to either keep the ComfyUI window in front (fine for a second screen setup) or jump straight to the OSC or gamepad nodes, which don't have that limitation. It's a real, documented quirk, not a bug in your install.

How to install

Install is the shared pack story. ComfyUI Manager → search "ComfyUI Web Viewer" → install, or:

cd ComfyUI/custom_nodes
git clone https://github.com/VrchStudio/comfyui-web-viewer
cd comfyui-web-viewer
pip install -r requirements.txt

Restart ComfyUI after. Windows portable: python_embeded\python.exe -m pip install -r ComfyUI\custom_nodes\comfyui-web-viewer\requirements.txt. No models to fetch.

The obvious follow-up question is "why not just type a number?" Because typing a number is a planning action and scrubbing is a performing action. When you're iterating on an interactive piece - nudging how much a face moves, how much denoise a live feed gets - you want muscle memory, not a text field. That's the niche this node owns, and it owns it with basically zero setup cost. If you find yourself reaching for the mouse mid-run, this is the node you were looking for.